struvite and weddellite

Topics: Apatites; Calcium Compounds; Calcium Oxalate; Calcium Phosphates; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Magnesium Compounds; Minerals; Names; Phosphates; Struvite; Urinary Calculi

To assess the potential of automated machine-learning methods for recognizing urinary stones in endoscopy.. Surface and section images of 123 urinary calculi (109 ex vivo and 14 in vivo stones) were acquired using ureteroscopes. The stones were more than 85% 'pure'. Six classes of urolithiasis were represented: Groups I (calcium oxalate monohydrate, whewellite), II (calcium oxalate dihydrate, weddellite), III (uric acid), IV (brushite and struvite stones), and V (cystine). The automated stone recognition methods that were developed for this study followed two types of approach: shallow classification methods and deep-learning-based methods. Their sensitivity, specificity and positive predictive value (PPV) were evaluated by simultaneously using stone surface and section images to classify them into one of the main morphological groups (subgroups were not considered in this study).. Using shallow methods (based on texture and colour criteria), relatively high sensitivity, specificity and PPV for the six classes were attained: 91%, 90% and 89%, respectively, for whewellite; 99%, 98% and 99% for weddellite; 88%, 89% and 88% for uric acid; 91%, 89% and 90% for struvite; 99%, 99% and 99% for cystine; and 94%, 98% and 99% for brushite. Using deep-learning methods, the sensitivity, specificity and PPV for each of the classes were as follows: 99%, 98% and 97% for whewellite; 98%, 98% and 98% for weddellite; 97%, 98% and 98% for uric acid; 97%, 97% and 96% for struvite; 99%, 99% and 99% for cystine; and 94%, 97% and 98% for brushite.. Endoscopic stone recognition is challenging, and few urologists have sufficient expertise to achieve a diagnosis performance comparable to morpho-constitutional analysis. This work is a proof of concept that artificial intelligence could be a solution, with promising results achieved for pure stones. Further studies on a larger panel of stones (pure and mixed) are needed to further develop these methods.

Topics: Artificial Intelligence; Cystine; Humans; Struvite; Uric Acid; Urinary Calculi

To predict the main component of pure and mixed kidney stones using dual-energy computed tomography and machine learning.. 200 kidney stones with a known composition as determined by infrared spectroscopy were examined using a non-anthropomorphic phantom on a spectral detector computed tomography scanner. Stones were of either pure (monocrystalline, n = 116) or compound (dicrystalline, n = 84) composition. Image acquisition was repeated twice using both, normal and low-dose protocols, respectively (ND/LD). Conventional images and low and high keV virtual monoenergetic images were reconstructed. Stones were semi-automatically segmented. A shallow neural network was trained using data from ND1 acquisition split into training (70%), testing (15%) and validation-datasets (15%). Performance for ND2 and both LD acquisitions was tested. Accuracy on a per-voxel and a per-stone basis was calculated.. Main components were: Whewellite (n = 80), weddellite (n = 21), Ca-phosphate (n = 39), cysteine (n = 20), struvite (n = 13), uric acid (n = 18) and xanthine stones (n = 9). Stone size ranged from 3 to 18 mm. Overall accuracy for predicting the main component on a per-voxel basis attained by ND testing dataset was 91.1%. On independently tested acquisitions, accuracy was 87.1-90.4%.. Even in compound stones, the main component can be reliably determined using dual energy CT and machine learning, irrespective of dose protocol.. • Spectral Detector Dual Energy CT and Machine Learning allow for an accurate prediction of stone composition. • Ex-vivo study demonstrates the dose independent assessment of pure and compound stones. • Lowest accuracy is reported for compound stones with struvite as main component.

Topics: Algorithms; Calcium Oxalate; Calcium Phosphates; Cysteine; Humans; Kidney Calculi; Machine Learning; Neural Networks, Computer; Phantoms, Imaging; Struvite; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi; Xanthine

We present in this paper accurate and reliable Raman and IR spectral identification of mineral constituents in nine samples of renal calculi (kidney stones) removed from patients suffering from nephrolithiasis. The identified mineral components include Calcium Oxalate Monohydrate (COM, whewellite), Calcium Oxalate Dihydrate (COD, weddellite), Magnesium Ammonium Phosphate Hexahydrate (MAPH, struvite), Calcium Hydrogen Phosphate Dihydrate (CHPD, brushite), Pentacalcium Hydroxy Triphosphate (PCHT, hydroxyapatite) and Uric Acid (UA). The identification is based on a satisfactory assignment of all the observed IR and Raman bands (3500-400c m(-1)) to chemical functional groups of mineral components in the samples, aided by spectral analysis of pure materials of COM, MAPH, CHPD and UA. It is found that the eight samples are composed of COM as the common component, the other mineral species as common components are: MAPH in five samples, PCHT in three samples, COD in three samples, UA in three samples and CHPD in two samples. One sample is wholly composed of UA as a single component; this inference is supported by the good agreement between ab initio density functional theoretical spectra and experimental spectral measurements of both sample and pure material. A combined application of Raman and IR techniques has shown that, where the IR is ambiguous, the Raman analysis can differentiate COD from COM and PCHT from MAPH.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Struvite; Uric Acid

Determine stones composition of the upper urinary tract in the eastern region of Algeria.. Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy.. The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randall's plaque.. Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend.. 4.

Topics: Adult; Aged; Algeria; Antioxidants; Apatites; Calcium Oxalate; Female; Hemostatics; Hospitals; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Prevalence; Retrospective Studies; Risk Factors; Sex Distribution; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid

This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi.. A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis.. A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p<0.001). The DE ratio could confidently differentiate uric acid, struvite, calcium oxalate, and carbonate apatite calculi (p<0.001) with cutoff values of 1.12, 1.34, and 1.66, respectively, giving >80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv.. Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.

Topics: Adult; Apatites; Calcium Oxalate; Female; Humans; Image Interpretation, Computer-Assisted; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Radiation Dosage; Struvite; Tomography, X-Ray Computed; Ureteral Calculi; Uric Acid; Waist Circumference; Young Adult

Studies that evaluate the effect of age and gender on the stone composition are scarce. The aim of this study is to highlight the modification of epidemiological characteristics of this pathology according to patients' sex and age.. We studied 1269 urolithiasic patients ranging from 6 months to 92 years old and known as having urinary stones (752 males and 517 females). Stone analysis was performed respectively using a stereomicroscope and infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each.. The annual average incidence of new stone formation was 30.25 per 100,000 inhabitants. In 1041 patients (81%), calculi were located in the upper urinary tract. Children and old man were more affected by bladder stone. Calcium oxalate monohydrate remains the most frequent stone component even if its frequency fell according to age (63.2% in teenagers and 40.6% in elderly [p<0.05]) in favour of the increase of uric acid stones (3,5% in teenagers and 41.5% in elderly [p<0.05]). Struvite stones were rare (3.5%) and more frequent in children.. The analysis of these data shows that urinary stones in Tunisia are tending to evolve in the same direction as in industrialized countries.

Topics: Adolescent; Adult; Age Distribution; Age of Onset; Aged; Aged, 80 and over; Calcium Oxalate; Child; Child, Preschool; Developing Countries; Female; Humans; Incidence; Infant; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Sex Distribution; Social Change; Spectrophotometry, Infrared; Struvite; Tunisia; Uric Acid; Young Adult

The qualitative and quantitative analyses of crystalluria have clinical significance in the diagnosis and prognosis of urolithiasis. The aim of this paper is to provide a new accurate methodology to get qualitative and quantitative data on urine particulate in patients with renal stone disease.The procedure involves a urine collection, the separation of the solid residual by centrifugation, and its analysis by X-ray diffraction, utilizing a micro-diffractometer in order to analyze very low amounts of residual. The spectrum obtained was converted into 2 θ -I profiles and quantitatively refined by Rietveld method. The proposed methodology has the advantage to accurately quantify all crystalline phases and the amorphous component of the urine; anyway urine samples have to be centrifuged and analysed as soon as possible, because the quantitative results obtained by the X-ray microdiffraction showed that after some days and at room temperature urine increased significantly both amorphous and crystalline phases.

Topics: Adult; Aged; Calcium Oxalate; Case-Control Studies; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Reproducibility of Results; Struvite; Temperature; Time Factors; Uric Acid; Urolithiasis; X-Ray Diffraction

In this work 85337 urinary stones were analysed by X-ray diffraction in regard of their qualitative and quantitative composition. Urological practitioners and hospitals from all areas of the former FRG sent urinary stones to the Institute of Mineralogy in Bonn and to the Urology Department of the St Josef-Hospital in Troisdorf up to December 31st, 1994. The evaluations were carried out with special regard to the frequency of occurrence and to the quantity portions. The frequency of occurrence of one component describes the percentage of the urinary stones which contain this component. The quantity portion describes the average amount of one component in regard to all urinary stones which contain this component as well. The frequency of occurrence of whewellite was 75.77% and of wheddellite 46.41%. 34.25% of all calculi were monomineralic and 55.3% were bimineralic.

Topics: Adolescent; Adult; Age Factors; Aged; Apatites; Calcium Oxalate; Child; Child, Preschool; Cross-Sectional Studies; Crystallography, X-Ray; Female; Germany; Humans; Infant; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Struvite; Uric Acid; Urinary Calculi

We have extended our previous observation that the percent occurrence of calcium oxalate stones decreased while that of calcium phosphate stones increased with each new stone event.. The National VA Crystal Identification Center has analyzed veteran patient urinary tract stones from VA hospitals throughout the United States since 1983. We reviewed the composition of 33,198 stones with emphasis on the changes in composition. More than 11,786 stones came from 5,088 recurrent stone formers. Stones were analyzed using high resolution x-ray powder diffraction and Fourier transform infrared spectroscopic techniques. When the stones were investigated as a function of time, it was determined that there was greater variability when samples were more than 30 days apart.. The percent occurrence of whewellite, weddelite, apatite, brushite and uric acid in stones increased between 1.0% and 5.9% since our previous study. The percent occurrence of struvite decreased by 2.6%. The percent of calcium oxalate stones decreased while that of calcium phosphate stones increased with each new event. However, the total percent occurrence of all calcium containing stones did not significantly change with recurrent stone events.. Our study suggests a strong trend for the conversion of stone disease from calcium oxalate to calcium phosphate containing stones, which could influence the progression and severity of disease.

Topics: Apatites; Calcium Oxalate; Calcium Phosphates; Humans; Magnesium Compounds; Phosphates; Recurrence; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

The successful fragmentation of kidney stones by means of extracorporeal shock wave lithotripsy partly depends on stone composition. In case of incomplete or coarse fragmentation, multiple urological procedures following ESWL may be necessary for removal of obstructive fragments. It is difficult to be sure that a given stone will be successfully destroyed. X-ray examinations before treatment are useful to classify calculi as calcium stones or not. Nevertheless, such investigations are often not sufficient to identify the main crystalline phases which form the stone and that can make it either resistant or friable to ESWL.. The aim of this study was to compare crystalluria and stone composition in patients with kidney calculi.. Seventy-five untreated patients (54 males, 21 females) were included. Their first morning urine was collected three days before surgical removal of the stone. Urine samples were kept at 4 degrees C during 48 hours before examination.. Crystalluria occurred in 97.3% of urine specimens. Weddellite was the most frequent crystalline species found in urine (66.2%), followed by carbapatite (33.1%) and whewellite (23.1%). When compared to stone composition, crystalluria was mainly made of weddellite in urines from 68% of patients with weddellite-rich calculi. Stones from patients presenting with whewellite crystals in urine were mainly composed of whewellite in 88.9% of cases. Struvite stones were associated with struvite and carbapatite crystalluria in 85.7% of cases.. Crystalluria studies could be of clinical interest to predict the main crystalline phase of calcium-containing stones in order to define the best procedures for stone removal.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Crystallization; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Microscopy, Polarization; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid

In regard to identify the compositions of urinary stones, the infrared spectra is a contemporary routine method. However, it is difficult to detect the absorption of carbonate in struvite stone by infrared spectra, because NH4 absorption of magnesium ammonium phosphate overlaps CO3 absorption of carbonate at 1420-1435 cm-1. With the purpose of demonstrating the existence of carbonate in struvite stones, the analysis of these stones by means of Raman spectra has been tried.. Forty urinary stones, the chemical compositions of which were previously determined by infrared spectroscopy, were submitted to Raman spectrum analysis, and subsequently to analysis by x-ray diffraction.. Thirty of 40 urinary stones were found to be composed of struvite and of mixed struvite-calcium oxalate by infrared analysis. Twelve of these stones were shown to have Raman spectra of magnesium ammonium phosphate, and the other stones to have spectra of apatite. By x-ray diffraction magnesium ammonium phosphate crystals were detected in 25 of these struvite stones and hydroxyl-apatite in another 3, and 2 cases were undeterminable. For other components, such as calcium oxalate, uric acid and cystine, the analytical results of infrared spectra coincided with those of Raman spectra and x-ray diffraction. Carbonate was detected in only a part of one struvite stone by Raman spectra.. Above-mentioned results may indicate that carbonate is only a minor component of urinary stones. Therefore, most of 1420-1435 cm-1 bands on the infrared spectra of struvite stones do not indicate CO3 absorption of carbonate, but NH(4) absorption of magnesium ammonium phosphate.

Topics: Calcium Oxalate; Carbonates; Female; Hemostatics; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Struvite; Urinary Calculi; X-Ray Diffraction

The internal-standard method and the powder diffractometer have been applied here to the quantitative determination of urinary stone constituents by x-ray diffraction (XRD). Reference intensity ratios determined for six stone substances were used in the reduction of intensity data. Constituent concentrations calculated for 21 stones were compared with values obtained from an element-sensitive technique. We conclude that XRD analysis alone cannot be regarded as a routine technique for the quantitative characterization of uroliths, but that semiquantitative XRD analysis supplemented by accurate quantitative elemental data is more suitable for the precise determination of true stone composition.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

Of 5 analysis tests of the 3rd International Ring Experiment for the control of the quality of methods of the analysis of urinary calculi 38 findings compiled according to 9 different techniques came in from 12 countries. The average deviation per component concerning all 5 analysis tests is considerably low with 0.10 mol proportions. The average quality measure SQ concerning all participants is approximately 2.00; it deteriorates from the X-ray diffraction method over the IR-technique to the other quantitative methods used. Advantages and disadvantages of the X-ray diffraction and IR-spectroscopic analysis are discussed. A methodically homogeneous and centralized performed analysis of urinary calculi shows advantages in the quality of the analyses.

Topics: Apatites; Calcium Oxalate; Germany, East; Humans; International Cooperation; Magnesium; Magnesium Compounds; Microchemistry; Microscopy, Polarization; Phosphates; Quality Control; Spectrophotometry, Atomic; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

Topics: Adult; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urinary Calculi; X-Ray Diffraction

The mineral composition of 103 stones from Iran was determined by a polarisation microscope and infrared spectroscopy. The commonest components were whewellite (81.5%), weddellite (40.7%), apatite (69%) and ammonium acid urate (24.4%). Ectopic cossification in the nuclei was found in three renal calculi (2.9%). Twenty-five stones were from children, where one of the most frequent patterns was formed by both ammonium acid urate and calcium oxalate. This suggests that a high proportion of the children from Iran with urolithiasis have nutritional disorders.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Hydroxyapatites; Iran; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Microscopy, Polarization; Minerals; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Bladder Calculi

Topics: Calcium Oxalate; Calcium Phosphates; Centrifugation, Density Gradient; Chemical Fractionation; Chemistry Techniques, Analytical; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction